1. Field of the Invention
The present invention is directed to testing reagents, and in particular, to devices and methods for simultaneously dispensing a plurality of microarray droplets of reagents onto a slide for use in testing biological and/or chemical interactions.
2. Description of Related Art
In the pharmaceutical and medical industries, it is often necessary to run numerous tests on a variety of different reagents. These tests include the analysis of chemical samples, biological samples, drug interactions, drug activity, testing for diseases and sickness, diagnostic tests, and the like. A number of such tests require the analysis of multiple samples in a single run. As the demand continues to increase for both existing tests, and for new tests and drug discoveries, the requirement for multiple sampling through-put remains high. This is particularly true for testing the endless possibilities of combinations of reagents, such as reagents A1-Zn, where n can be on the order of millions, for use in the research and development of new drug discoveries and testing procedures.
It is well known to use plastic well plates for supplying the various chemicals and biological samples for contact and interaction of these substances within the wells. For example, commercially available plastic card arrays include 96 and 384 wells, having diameters typically of about 3 mm to about 4 mm, and depths of about ½ inch. However, it has been found that plastic well plates undesirably use large quantities of expensive chemicals and/or reagents, and obtain very few data points simultaneously. Further, since plastic well plates are formed by extrusion, the precision of the hole diameter and location within the array is not adequate enough to fabricate micro holes and micro channels required for newer technologies. In the event well opening diameters and locations are not to exact specifications, the precision of both analytical instrumentation used in introducing the chemicals and reagents into the well openings, as well as instrumentation for scanning the well openings, will be imprecise. Thus, the extension of plastic well plates into this field is limited.
With the currently available technology, a large number of samples can now be scanned in a single run due to the speed of computer assisted scanning devices. For instance, microfluidic scanning devices allow for the integration and miniaturize of multiple laboratory processes into a single conventional chip size device by increasing the number of well openings in a given volume within the well plate. Thus, the need remains high for an increased number of smaller micro holes and channels within a given volume in the well plate. The implementation of a larger number of smaller micro holes and channels reduces the consumption of expensive chemicals and/or reagents used during the analysis or testing, which in turn, lowers manufacturing costs, increases sample throughput, provides faster end results due to the faster analysis, provides high performance and success, and allows for an enormous scope of integration and ease of automation with the various available instrumentation. Such a micro device would be particularly beneficial for dispensing numerous, small amounts of reagent onto a glass test slide (i.e., “microspotting”), which is then dried for later diagnostic and/or experimental use.
Accordingly, a need continues to exist for micro devices that have multiple thousands of wells with diameters of the order of 100 microns and channels connecting the selective wells at different levels within the array for dispensing small amounts of reagents, particularly onto a test slide.